Grey partridges (Perdix perdix) and European hares (Lepus europaeus) originated on the Eurasian steppes. The prehistoric introduction of agriculture to Europe lead to both species thriving and establishing across the continent, becoming culturally and economically important to human communities throughout. However, the intensification of agriculture practices in the past century, particularly the last 60 years, has led to the decline of these iconic native European species.

The initial drastic decline of partridges from 1950-1980 is believed to have been caused by the widespread increase in pesticide use, which resulted in lower insect availability for protein hungry chicks. While the decline since the 1980s, is assumed to have been due to a combination of the loss of habitat structure and predation. These last two factors are also deemed responsible for the decline of hare populations. The advent of large scale mechanised farming resulted in a huge reduction in habitat structure, which includes hedgerows, field margins, fallow land, dead grass etc. Such structures not only provides nesting sites, food, and thermal refuges for both species but can also shield them from potential predators, such as foxes, martens, and harriers. This interaction between these two factors and the variation in local conditions, especially historical and recent agricultural and hunting practices, can make it difficult to tell which of these factors is the major cause of a population’s decline.

We intend to disentangle the contribution of these factors to the decline of partridge and hare populations in lower Austria. To do this we will use a mixture of established and new methods in Baden, lower Austria. We plan to place artificial nests along with fake eggs in different parts of partridge habitat to test how nest predation varies with habitat structure. We will also use the latest biologging techniques. Biologging involves putting a sensor, usually within a collar, on an animal to gain information about its movement, behaviour, physiology, and/or environment. We plan to place such equipment on partridges, hares, foxes, and martens to see how each species uses the environment at a very fine scale.

This will allow us to answer a wide range of questions including:

• In what type of habitat do partridges naturally lay their eggs?
• How does partridge/hare habitat use change seasonally?
• How does partridge and hare habitat use change with the presence of a predator?
• What habitat structures are predators using?
• Does predator habitat use change seasonally?
• Does predation increase when prey experience heat stress?

The answers to these questions will be of vital importance in reversing the decline of partridge and hare populations of lower Austria and Europe, more broadly. However, they will also provide crucial baseline information before the changes enacted by “The Austrian Program for the promotion of environmentally friendly, extensive agriculture that protects natural habitats” (Österreichische Programm zur Förderung einer umweltgerechten, extensiven und den natürlichen Lebensraum schützenden Landwirtschaft, ÖPUL 2023) begin to effect farmland ecosystems. In addition, an understanding of behaviour under current climatic conditions may provide insights into the possible effects future temperature and precipitation extremes will have on these two charismatic European species. This information will be used in sophisticated computer models—known as mechanistic niche models or biophysical models—to predict the future distribution of each species under various potential future climate scenarios, therefore aiding in the management and protection of these two charismatic European species well into the future.

Funding

The project is funded by the Society for the Advancement of the Institute of Wildlife Ecology ("Fördges").